1. Field of the Invention
The invention relates to a multiplex slide plate device for molecular biological detection and an operation method thereof, and more specifically, to a multiplex slide plate device prefilled with polymerase chain reaction (PCR) reagent(s) and an operation method thereof.
2. Description of Related Art
In the field of molecular biological detection, a multiplex test may be required to simultaneously measure multiple biomolecules of a biological sample in a single run/cycle of the test. For example, measuring several single-nucleotide polymorphism (SNP) genotypes, or the expression levels of a number of genes of a sample via polymerase chain reaction (PCR) assays. At this time, multiple DNA or RNA assays may compose a test panel. A PCR assay comprises at least two DNA specific primer probes (for some PCR assays also include additional target-specific reporter probes), and this pair of primers has to correctly mix with the DNA template extracted from the sample to be tested so as to measure the presence or the amount of the specific DNA targets in the sample.
Traditionally, the pair of primers and the sample are delivered to the same reaction vessel for PCR. The delivery is usually done by pipetting the solution from each vial which stores primer pairs, enzymes and reagents, and pipetting the sample, to the reaction vessel. The most common vessel format is the 96-well titter plate. In such way, a PCR assay requires at least two pipettings, one for adding the primer pairs and another one for adding the sample to the reaction vessel. For example, for a panel to examine 36 targets in one sample, it needs at least 36 pipettings to add each pair of primers to 36 different reaction vessels, and another 36 pipettings to add sample to each of the above reaction vessels. This part of operation method is not only complicated and error-prone, but also labor-intensive.
If the primer pairs are pre-filled in each of the reaction vessels, the PCR experiment operator only needs to add sample to the pre-filled vessels. The above mentioned example of detecting one sample for 36 targets would require only 36 pipettings for adding sample to 36 pre-filled vessels. Besides, the reaction vessel volume can be reduced to nano-liter range to save the amount of reaction reagents. The result format of 96-well titter plate, which is a common carrier vessel, is changed into a slide-like micro-titter plate by this improvement.
However, the size and volume of reaction vessels (also called micro-wells or nano-wells) in a micro-titer plate are too small to be filled with the primer pairs or samples manually without causing cross-contamination between neighbouring vessels (i.e. the primer pairs escape from one well to other wells). Therefore, the microfluidic technology or system for dispensing primer pairs or samples is required. In more detail, primer pairs are delivered to each of the nano-wells in advance and immobilized onto the inter-surfaces of the nano-well. Afterwards, the user can apply the sample to each of the reaction vessels by single pipetting operation or single microfluidic channel without worrying about primers escaping from one well to other wells, such that the cross-contamination between wells is minimized.
When the sample testing is performed subsequently, each reaction vessel must be filled with the predetermined amount of sample. The traditional method is to use pipette or needle dispensers to load the sample “one by one” into the reaction wells. However, as the volume of reaction vessel becomes smaller and the inter-well distance becomes closer, special mechanical system or paths may be needed for the dispenser to reach each reaction vessels individually, which is complicated and time-consuming. If adding sample into each of the reaction vessels by single pipetting operation or single microfluidic chaimel can be achieved by a special slide plate device, it is possible to greatly simplify the manual operation required in PCR reagent preparation, and enhance the convenience when sample filling.